Warp3 Posted March 21, 2004 Share Posted March 21, 2004 Well yesterday, a friend and I replaced the bad radiator in my 86RX (along with a bunch of other parts: radiator hoses, radiator cap, 180-degree thermostat, fuel filter, and drive belts). Also found out during the install that the thermosensor on the old radiator wasn't even plugged in. Good news: - car is absolutely purring at idle - temp gauge is hanging around 1/3-1/2 and not budging even when driven very hard Bad news: - fixing parts of the cooling system simply found other weaknesses: the car blows coolant all over the engine bay from the upper turbo coolant hose now (but only under boost...is that normal to only have that hose pressurized under boost? ). Do parts stores sell the "turbo coolant hoses" (my friend seems to think they wouldn't and I would need to just buy heater hose in the appropriate diameter) or should I just get these from the dealer? - the fuel filter didn't fix my "stumbling issue" as I had hoped (the car "stumbles" under acceleration and is most noticeable when the engine is cold and at partial throttle). I'm thinking the IAC valve as my next possibility (as the back of the plug on it appears to be halfway falling off anyway (though the wires inside are still solidly connected)) but any suggestions would be very welcome. Quote Link to comment Share on other sites More sharing options...
WJM Posted March 21, 2004 Share Posted March 21, 2004 DONT use standard heater hose...it will fail. The ultra high heat of the coolant comming out of the turbo will cook that hose...and the lower hose will be cooked by the exhaust peieces surrounding it. Go with the OEM hoses. They have heat shields, and are made of a special silicone/rubber substance that puts up to the heat. OR....ask Steven what we did with the RX.....braided steel lines! And some speical heat shielding... I am betting the IAC is the stumble issue. Quote Link to comment Share on other sites More sharing options...
Warp3 Posted March 23, 2004 Author Share Posted March 23, 2004 After going to the dealership, I'm honestly not convinced that the *upper* turbo coolant hose is anything special. The lower hose is obviously heat-shielded and costs like $23. The upper hose on the other hand is only $3 and appears to simply be a straight piece of hose (according to the service manual and what's on my car) so I'm not convinced its anything more than just coolant/heater hose. Regardless I was planning to order one anyway...until we found out that even though the part is still "orderable" (because, to quote the parts guy, it's not listed as "obsolete"), the current warehouse stock in the U.S. is ZERO (plenty of the expensive lower hose that I don't need, though...LOL). So what next? It's been suggested to me that fuel line should work for this application...is this correct? Quote Link to comment Share on other sites More sharing options...
baccaruda Posted March 23, 2004 Share Posted March 23, 2004 the top coolant hose is silicone coolant hose. you can get it in bulk by the foot from Napa and many other places. the reason it's only coming out under boost is because it's at higher RPMS. your water pump is turning at higher RPMs too and causing it to squirt. keep your coolant full until you fix it; it will make it easier to squirt out, but that's good because it it stops squirting, it means you're too low on coolant! fix that top coolant hose ASAP. You WILL need to change the coolant return hose underneath (with the foil heat reflector, the $23 hose you mentioned) ... at the same time you should do that, you should replace the oil return hose because they are both equally inconvenient to get to. You may want to pull the downpipe and turbo (and heat shields) off to get to them, as well perhaps as the passenger's side axle. I changed mine from underneath without pulling the turbo up, and it might have been easier with the turbo loosened. You might not have to disconnect the oil inlet (hard line), just don't damage it moving the turbo off the downpipe. ALSO since you have the turbo off the crossover pipe, you might replace the turbo to X-over pipe and turbo to crossover pipe gaskets, as well as the exhaust manifold gaskets that go to the crossover pipe. You might also change the other little coolant hoses on top of the block.. this is all worth a LOT of peace of mind to a turbo car owner, and not as much work as I may have made it sound. good luck! Quote Link to comment Share on other sites More sharing options...
Meeky Moose Posted March 24, 2004 Share Posted March 24, 2004 i still need to go buy a new lower turbo coolant line... it was a weekend, and i had to go to the parts store and get some funky coolant hose for a jeep or explorer.. its rubber but it looked like it was very heavily braided on the inside as you could see the ribs in the rubber. i then reused the heat shielding off of 2 bad lines and wrapped it up good.. been on there for about 1000 miles so far and no troubles.. but yes i know i need to go order one from the dealer.. the top line is (like stated above) a straight piece of silicone hose.. (i had an oem hose in my glovebox as a spare, so i used it) Quote Link to comment Share on other sites More sharing options...
Warp3 Posted March 24, 2004 Author Share Posted March 24, 2004 Originally posted by baccaruda the top coolant hose is silicone coolant hose. That's about what I was guessing it was...thanks! keep your coolant full until you fix it {...} fix that top coolant hose ASAP. Well, fortunately, I have the Impreza so I'm just leaving the RX sitting at home until I acquire a new hose. You WILL need to change the coolant return hose underneath (with the foil heat reflector, the $23 hose you mentioned) ... at the same time you should do that,{...lots more stuff...} Ummm...:-\ Unless that hose starts leaking, I think I'll hold off on that project until I see what happens with the TWE crossover/downpipe group buy and replace it then. BTW...anybody know offhand what diameter the upper turbo coolant hose is? I didn't drive the RX today and if I can find out what size I need before I leave work today, I can stop by the auto parts store on my way home. Quote Link to comment Share on other sites More sharing options...
Warp3 Posted March 24, 2004 Author Share Posted March 24, 2004 Wait... On second thought, I already have some silicone hose that I bought to replace my vacuum lines...would that work or is silicone coolant hose different? (What I have is shown here: http://store.summitracing.com/partdetail.asp?part=AVC%2D51005&view=2047) EDIT: Never mind...from what I'm finding on the web, silicone coolant hose is quite different from silicone vacuum hose. Quote Link to comment Share on other sites More sharing options...
rallyruss Posted March 24, 2004 Share Posted March 24, 2004 use 1/2" silicone heater hose. works great. I made the rubber hose mistake already. it lasted a couple thousand miles then blew 2 hours from home. had to get real creative there. but thanks to a bus driver and some mormon misionarys that helped out I got it all fixed in no time. then I went and got the silicone hose. as for your stumble try disconecting the egr vac line and pluging it. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.